Pipe Fusion Machine

ABSTRACT

One fusion machine can butt or socket fuse polyolefin pipes and fittings in straight alignment or at inwardly or outwardly mitered universal angles from 0° to 45° for butt fusion and from 0° to 10° for socket fusion. The machine is manually driven, hydraulically monitored and operated in all configurations from one side of the machine.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of and claims the priority of U.S.patent application Ser. No. 15/709,470 titled “PIPE FUSION MACHINE,”filed Sep. 20, 2017, the contents of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

This invention relates generally to pipe fusion machines and, moreparticularly, concerns a pipe fusion machine with butt and socket fusioncapabilities.

Known butt fusion machines use low accuracy force measuring devices suchas spring scales that may lead to inferior joint quality. Their forcescales are hard to read with course granularity causing the operator tohave to estimate or interpolate the force they are using. They do nothave the force capabilities to handle high drag situations. They have atbest only 15° of miter angle capability in their targeted pipe sizerange, thus requiring the operator to perform more fusions when creatinglarger radius bends. Their jaws pivot in only one direction, requiringthe operator to rotate the machine or rotate the work piece to create anoffset. They employ inconveniently located input mechanisms, causing theoperator to provide the input force in a manner not conducive toergonomic operation. They do not have the capability to adapt jointmonitoring devices. They do not support pipes that rotate with theirjaws throughout the miter fusion range, possibly resulting in suboptimal joints. They require the use of tools to adjust theconfiguration of machine, lowering the productivity of the operator. Andthey cannot be used for socket fusion.

Known socket fusion machines cannot create joints with slight miterangles, thus necessitating the use of fittings or bend pipe to routearound obstacles and increasing cost and causing undue stress on thepipes. They cannot monitor the force used to join the pipe, makingverification of use of proper fusion procedure more difficult. And theycannot be used cannot be used for butt fusion, whether mitered orstraight.

It is, therefore, an object of this invention to provide a pipe fusionmachine capable of use for both butt and socket fusion. Another objectof this invention is to provide a pipe fusion machine that provides awide range of angles universally selectable for mitered fusion. It isalso an object of this invention to provide a pipe fusion machine thatmonitors forces with high accuracy. A further object of this inventionis to provide a pipe fusion machine configured to be operator friendlyin performance of the fusion processes. And it is an object of thisinvention to provide a pipe fusion machine that can be adjusted to avariety of fusion applications without the use of tools.

SUMMARY OF THE INVENTION

In accordance with the invention, a pipe fusion machine has a frame witha reference end and a drive end supporting spaced apart parallel guiderails therebetween in a horizontal plane. A vertically aligned fixedbearing is centered between the guide rails on the reference end of theframe. A carriage is mounted for longitudinal sliding reciprocation onthe guide rails toward and from the reference end of the frame. Acarriage drive mechanism proximate the drive end of the frame and has adrive gear and drive shaft in a connection adapted to reciprocate thecarriage on the guide rails in response to rotational directional forcemanually applied to the drive mechanism and to permit independent freeaxial motion of the drive shaft in relation to the drive gear. Ahydraulic system with a piston and cylinder is co-operable with thecarriage drive mechanism so that, when carriage is met with resistanceto axial travel, the drive shaft slides axially in the drive gear tocause the piston to compress fluid in the cylinder.

The connection of the drive mechanism and the piston and cylinder of thehydraulic system are further co-operable, at a point of cessation ofmotion of the carriage, to maintain the carriage at the point ofcessation of motion. The pressure of the compressed fluid can bemonitored by a transducer and/or a pressure gauge.

For fusing pipe in straight or mitered alignment, whether for butt orsocket fusion, a pipe fusion machine has a frame a reference end and adrive end supporting spaced apart parallel guide rails in a horizontalplane. A carriage is mounted to slide longitudinally on the guide rails.One vertically aligned bearing is centered between the guide rails onthe reference end of the frame. Another vertically aligned bearing iscentered between the guide rails on the carriage. Each of the verticallyaligned bearings has an identical clamping mechanism thereon. A carriagedrive mechanism proximate the drive end of the frame is configured toreciprocate the carriage on the guide rails in response to directionalforce applied to the carriage. A fixed butt fusion jaw and a fixedsliding fusion jaw are each adapted for mounting on the frame bearing. Asliding butt fusion jaw and a sliding socket fusion jaw are each adaptedfor mounting on the carriage bearing. Each of the jaws is adapted forengagement with a corresponding clamping mechanism of a correspondingbearing. Each clamping mechanism is operable between a jaws-releasedcondition and a jaws-locked condition and adapted so that in thejaws-locked condition the clamping mechanisms are able to securecorresponding fixed and sliding butt fusion jaws or corresponding fixedand sliding socket fusion jaws on the frame and carriage bearings,respectively.

Each of the jaws is further adapted to permit its rotation about itscenter vertical axis in its corresponding bearing in the jaws releasedcondition. Rotation of the jaws about their respective axes is forwardand rearward of the vertical plane centered between the guide rails. Theframe and the carriage each have an identical rotational index and eachjaw has an angle registration line at the vertical plane co operablewith a corresponding index to universally indicate an angular positionof the jaw in relation to its respective frame or carriage. Each jaw mayfurther have a telescoping pipe support mounted on and rotatable withthe jaw.

For use in socket fusion of polyolefin pipe at mitered angles, themachine has a frame with a reference end and a drive end supportingspaced apart parallel guide rails therebetween in a horizontal plane. Acarriage is mounted to slide longitudinally on the guide rails. Onevertically aligned bearing is centered between the guide rails on thereference end of the frame. Another vertically aligned bearing iscentered between the guide rails on the carriage. Each of the verticallyaligned bearings has an identical clamping mechanism thereon. A carriagedrive mechanism proximate the drive end of the frame is configured toreciprocate the carriage on the guide rails in response to directionalforce applied to the carriage. A fixed socket fusion bracket is adaptedfor mounting on the frame bearing. A sliding socket fusion bracket isadapted for mounting on the carriage bearing. Each of the brackets isadapted for engagement with a corresponding clamping mechanism of acorresponding bearing. The clamping mechanisms are operable between abrackets-released condition and a brackets-locked condition and areadapted in their brackets-locked condition to secure the fixed socketfusion bracket and the sliding socket fusion bracket on the frame andcarriage bearings, respectively. The fixed and sliding socket fusionbrackets each have a mechanical drive assembly supporting fixed andsliding socket fusion jaws, respectively, for opening and closing frontand rear components of respective jaws by sliding reciprocation to andfrom a center point between the guide rails of the carriage onrespective axes transverse to the guide rails.

Each of the brackets is rotatable about its center vertical axis forwardof and rearward of a vertical plane centered between the guide rails.The frame and the carriage each have an identical rotational index andeach bracket has an angle registration line at the vertical planeco-operable with a corresponding index to universally indicate anangular position of the bracket in relation to a respective frame orcarriage.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings in which:

FIG. 1 is a perspective view of a pipe fusion machine according to theinvention configured for straight butt fusion;

FIG. 2 is a perspective view of a pipe fusion machine according to theinvention configured for straight socket fusion;

FIG. 3A is a perspective view of a fixed jaw assembly of the pipe fusionmachine in the configuration of FIG. 1;

FIG. 3B is a perspective view of a sliding jaw assembly of the pipefusion machine in the configuration of FIG. 1;

FIG. 4A is a perspective view of a fixed jaw assembly of the pipe fusionmachine in the configuration of FIG. 2;

FIG. 4B is a perspective view of a sliding jaw assembly of the pipefusion machine in the configuration of FIG. 2;

FIG. 5A is a cross-sectional view, taken in a horizontal plane bisectingthe guide rods of the frame, of the fixed and sliding jaw pivot bearingsof FIGS. 1 and 2;

FIG. 5B is a cross-sectional view taken along the line 5B-5B of FIG. 5A;

FIG. 6A is a perspective view of the fusion machine drive mechanism andhydraulic system mounted on the right end portion of the base of FIGS. 1and 2;

FIG. 6B is an enlarged top plan view of the drive mechanism andhydraulic system of FIG. 6A;

FIG. 6C is a schematic drawing of the hydraulic system of the pipefusion machine of FIG. 6A;

FIG. 7A is a top plan view of the pipe fusion machine configuration ofFIG. 1 adjusted for proximal mitered butt fusion relative to itsoperator;

FIG. 7B is a top plan view of the pipe fusion machine configuration ofFIG. 1 adjusted for distal mitered butt fusion relative to its operator;

FIG. 8A is a top plan view of the pipe fusion machine configuration ofFIG. 2 adjusted for proximal socket fusion relative to its operator;

FIG. 8B is a top plan view of the pipe fusion machine configuration ofFIG. 2 adjusted for distal socket fusion relative to its operator;

FIG. 9A is a top plan view of the adjusted pipe fusion machineconfiguration of FIG. 7A; and

FIG. 9B is a top plan view of the adjusted pipe fusion machineconfiguration of FIG. 8B.

While the invention will be described in connection with a preferredembodiment thereof, it will be understood that it is not intended tolimit the invention to that embodiment or to the details of theconstruction or arrangement of parts illustrated in the accompanyingdrawings.

DETAILED DESCRIPTION

Looking at FIG. 1, a machine M for fusing polyolefin pipes and fittingsis shown in a configuration for use in butt fusion. The term“polyolefin” identifies a most common application of the fusion machinebut is intended to include “nylon,” PVC and other fusible non-polyolefinpipes and fittings. Looking at FIG. 2, the same machine M is shown in aconfiguration for use in socket fusion.

As is seen in both FIGS. 1 and 2, the machine M has a frame 10 withfront and rear elongated, parallel, horizontal, spaced-apart guide rails11 and 12. A bearing 14 on reference end 15 of the frame 10 is centeredon a vertical reference plane 17 bisecting the space between the guiderails 11 and 12. A carriage 20 has front 21 and rear 22 cylinderssliding on the front and rear guide rails 11 and 12. A bearing 24 on thecarriage 20 is also centered on vertical reference plane 17. The outerside portions of the frame 10 and the carriage 20 have identicalrotational indexes 26 at the vertical reference plane 17. An index rangeof 22.5° to either side of the vertical reference plane 17 providestotal range of 45° degrees for a bearing 14 or 24. A manually operatedmechanical drive system 30 enables operator reciprocation of thecarriage 20 on the guide rails 11 and 12 of the frame 10. The drivesystem 30 has a hydraulic load system 31. The hydraulic load system 31is monitored by a transducer 32 and a pressure gauge 33. Preferably, andas shown in FIGS. 1 and 2, the frame bearing 14 and the carriage bearing24 are identical.

Comparing the butt fusion configuration of FIG. 1 with the socket fusionconfiguration of FIG. 2, the frame and carriage bearings 14 and 24 ofthe butt fusion configuration support butt fusion fixed and sliding jaws41 or 42, respectively, and the frame and carriage bearings 14 and 24 ofthe socket fusion configuration support socket fusion fixed and slidingjaws 43 and 44, respectively.

Turning to FIGS. 3A and 3B, the butt fusion fixed and sliding jaws 41and 42, respectively, are illustrated. The fixed and sliding jaws 41 and42 have mirror-imaged substantially circular clamps 45 and 46. Theclamps 45 and 46 are made of U-shaped cross-section channel 47 and 48and are sized to secure the largest diameter pipe of the range of pipesto be gripped by the jaw 41 or 42. In relation to the frame 10, theoutermost wall 51 of the channel 47 or 48 has a larger inside diameterthan the innermost wall 52 of the U-shaped channel 47 or 48. Therefore,only the edge of the innermost wall 52 will make contact with the pipeto be gripped. The channel 47 or 48 provides a groove 53 into whichadapters (not shown) sized for gripping smaller diameters of pipe withinthe range of the jaw 41 or 42 can be inserted. Each of the grippingedges of the channel 47 or 48, or any insert, may be serrated. The clamp45 or 46 is split into upper and lower segments 55 and 56 hinged at therear of the clamp 45 or 46 in spaced apart relationship by a linkage 54pivotally connected to each segment 55 and 56. A latch 58 mounted on thefront of the lower segment 56 of the clamp 45 or 46 has a lever 59engageable with the upper segment 55 of the clamp 45 or 46. The lever 59is spaced from the latch 58 by a linkage 57 pivotally connected to thelatch 58 and the lever 59. A screw 61 on the latch 58 engages a latchpivot 62 to permit adjustment of the force applied by the clamp 45 or46.

Looking at FIGS. 1 and 3A, the lower segment 56 of the butt fusion fixedjaw clamp 45 has a bracket 63 fixed on top of a post 64. Immediatelybelow the bracket 63, two concentric rings 65 and 66 define a groove 67.As seen in FIG. 1, the bracket 63 will be seated on the frame 10 withthe rings 65 and 66 and groove 67 disposed inside of the frame orreference bearing 14. The post 64 extends down to a seat 68 in the frame10. A telescoping pipe support 71 mounted on a clamp bracket extension72 is adjustable vertically to accommodate the diameter of the pipe tobe clamped in the fixed jaw 41.

Looking at FIGS. 1 and 3B, the lower segment 56 of the butt fusionsliding jaw clamp 46 has a transversely extending trapezoidalcross-section tongue 74. A bracket 75 with a complementary groove 76wider than the tongue 74 is fixed to the top of a post 77. The narrowertongue 74 slides in the wider groove 76 and can be locked in a desiredtransverse position by the operation of rear and front levers 78 againstthe gib 73 to pin the tongue 74 against the groove 76. As seen in FIG.1, the bracket 75 will be seated on the carriage 20 with the rings 65and 66 and the post groove 67 inside of the carriage bearing 24. Theconcentric rings 65 and 66 provide an identical groove 67 on the buttfusion sliding jaw clamp 46 as the groove 67 on the butt fusion fixedjaw clamp 45. As seen in FIG. 3B, the lower concentric ring 66 isdownwardly extended and has an arcuate channel 69 in its bottom surface.A telescoping pipe support 79 mounted on the grooved bracket 75 isadjustable vertically to accommodate the diameter of the pipe to beclamped in the sliding jaw 42.

Turning to FIGS. 4A and 4B, the socket fusion fixed and sliding jaws 43and 44, respectively, are illustrated. The socket fusion fixed jaw 43has a post 64 with concentric rings 65 and 66 and a groove 67 identicalto that of the butt fusion fixed jaw 41. However, the bracket 83 at thetop of the post 64 of the socket fusion fixed jaw 43 is not the same asthe bracket 63 at the top of the post 64 of the butt fusion fixed jaw41. The socket fusion sliding jaw 44 also has concentric rings 65 and 66and a groove 67 identical to that of the socket fusion fixed jaw 43. Andthe bracket 83 at the top of the post 64 of the socket fusion slidingjaw 44 is identical to that of the bracket 83 on the socket fusion fixedjaw 43. However, the lower concentric ring 66 of the socket fusionsliding jaw 44 is downwardly extended and has an arcuate channel 69 inits bottom surface.

Looking at FIGS. 2 and 4A, the socket fusion fixed jaw bracket 83supports a pair of elongated parallel guides 84 of a mechanical assembly80 in transverse relationship to the guide rails 11 and 12 of the frame10 and has a reference bearing 14 on the vertical reference plane 17.Front and rear segments 87 and 88 of the fixed jaw clamp 85 are engagedto slide on the parallel guides 84. The bracket 83 also supports thecenter point 89 of a horizontal transverse elongated screw 91 threadedoppositely on either side of the center point 89. The front segment 87of the fixed jaw clamp 85 is engaged on the front threaded portion ofthe screw 91 and the rear segment 88 of the fixed jaw clamp 85 isengaged on the rear threaded portion of the screw 91 symmetrically inrelation to the center bearing 89. Manual operation of a handle 93 onthe front end of the screw 91 in one direction closes the space betweenthe clamp segments 87 and 88 and in the opposite direction opens thespace between the clamp segments 87 and 88. The clamp 85 is shaped tosecure a pipe fitting in longitudinal alignment with the verticalreference plane 17. An adjustable brace 94 is telescopically mounted onthe outside of the fixed jaw 43 to prevent travel of the fitting awayfrom the jaw 43.

Looking at FIGS. 2 and 4B, the socket fusion sliding jaw clamp 86 isidentical to the socket fusion fixed jaw clamp 85 except that the clamp85 is shaped to secure a fitting and the clamp 86 is shaped to secure apipe in longitudinal alignment with the vertical reference plane 17 andhas no brace.

Looking now at FIGS. 1, 2, 5A and 5B, the rotational adjustability ofany of the butt fusion fixed and sliding jaws and socket fusion fixedand sliding jaws in their respective bearings can be understood. Withthe jaw rings 65 and 66 inserted into the bearings 14, 24 until thebracket 63, 75 or 83 strikes the top of the bearing 14, 24, at whichpoint the groove 67 lies in a horizontal plane 92 bisecting the guiderails 11 and 12, a clamp 95 is inserted through the bearing wall 96 intothe groove 67 to retain the jaw at that level in the bearing 14, 24. Therear end of the clamp 95 is bolted to the frame 10. A stud 98 extendsthrough the front end of the clamp 95 and the frame 10 and is securedagainst the frame 10 by a threaded handle 101 accessible to the operatorand a nut 99. The lower inside corner of the clamp 95 has a bevel 102and engages a complementary bevel 103 on the bottom of the groove 67.

When the operator has adjusted an angle registration line 28 on the jawat the vertical reference plane 17 with the desired angle on therotational indexes 26 of the respective frame 10 or carriage 20, theoperator can tighten the grip of the clamp 95 against the groove 67 ofthe frame 10 or carriage 20. When the clamp 95 is tightened it providesradial torsional resistance and axial force through the wedging actionof the bevels 102 and 103. The axial force also provides additionalresistance to torsional forces through the frictional interface betweenthe jaw and the frame 10. The axial force ensures the connection betweenthe jaw and the frame 10 is as tight as possible and provides anaccurate datum with which to reference the center line of the jaws.

This configuration affords the operator universal selectivity of theangle of the jaw within the range of the index. Typically, for buttfusion a range of 22.5° to either side of the vertical reference plane17 is used and for socket fusion a range of 5° to either side of thevertical reference plane 17 is used.

Turning now to FIGS. 6A and 6B, the mechanical drive system 30 of themachine M is mounted on the carriage side of the frame 10. The drivesystem 30 has an input, as shown a wheel 34 with a handle 35, mounted onan input shaft 36 extending to an input gear 37. From an operator'spoint of view, when the input wheel 34 is turned counter clockwise, theinput gear 37 is also turned counter-clockwise. An output gear 38engages with the input gear 37 to transfer counter-clockwise motionlooking at the front of the machine M 90° to clockwise motion lookingfrom the carriage 20 toward the reference end 15 of the frame 10. Thedrive gear 38 is connected by a noncircular, as shown a hex, adaptation39 for rotation with and axial motion in relation to, a driveshaft 110on a longitudinal axis 111 of the vertical plane 17. A drive screwextension 112 of the drive shaft 110 rotates with the drive shaft 110.The drive screw 112 is coupled to the carriage 20 by a drive nut 113.But the drive nut 113 is fixed rotationally so, when the drive screw 112is turned clockwise, the carriage 20 is translated axially toward thereference end 15 of the frame 10. When the carriage 20 is met withresistance to axial travel, it causes the drive shaft 110 to slideaxially in the drive gear 38 that, in turn, presses on a hydraulicpiston 114, compressing the fluid 115 in the hydraulic cylinder 116.

Looking now at FIGS. 6B and 6C, when the driveshaft slides 110 in thedrive gear 38, the adaptation 39 of the drive gear 38 and drive shaft110 allows torsional transmission of force with free axial movement.When the input motion ceases, the rotational force is eliminated and thecarriage 20 is held in position by the non-back driving nature of thedrive nut 113 and the drive screw 112 pushing the drive shaft 110 intothe piston 114 to compress the fluid 115 in the cylinder 116. As seen inFIG. 6C, as the drive shaft 110 moves through the drive gear 38 towardthe carriage end of the frame 10, it compresses a spring 117 in the loadcell piston 114 causing the piston to compress the fluid 115 in the loadcell housing 116 and increasing the pressure at the transducer port 32and the pressure gauge 33. The axial force remains and can be monitoredelectronically or hydraulically, as shown hydraulically, through analogor digital means due to the free sliding nature of the adaptation 39between the drive shaft 110 and drive gear 38.

When the input rotation is reversed by the operator, the carriage 20 iswithdrawn from the reference end 15 of the frame 10 pulling the driveshaft 110 out of the drive nut 113 and with it pulling the load cellpiston 114 in the load cell housing 116, releasing fluid pressure in thehousing 116 and on the transducer 32 and pressure gauge 33.

Turning now to FIG. 7A, for butt fusing pipe in a distal miteredalignment relative to the operator, the pipe fusion machine M has aframe 10 with a reference end 15 and a drive end 16 supporting spacedapart parallel guide rails 11 and 12 in a horizontal plane. The carriage20 is mounted to slide longitudinally on the guide rails 11 and 12. Onevertically aligned bearing 14 is centered between the guide rails 11 and12 on the reference end 15 of the frame 10. The other vertically alignedbearing 24 is centered between the guide rails 11 and 12 on the carriage20. Each of the vertically aligned bearings 14 or 24 has a mirroredclamping mechanism 45 or 46 thereon. The carriage drive mechanism 30proximate the drive end 16 of the frame 10 is configured to reciprocatethe carriage 20 on the guide rails 11 and 12 in response to directionalforce applied to the carriage 20. The butt fusion fixed jaw 41 isadapted for mounting on the frame bearing 14. The butt fusion slidingjaw 42 is adapted for mounting on the carriage bearing 24. Each of thejaws 41 and 42 is adapted for engagement with a corresponding clampingmechanism 95 of a corresponding bearing 14 or 24. Each clampingmechanism 95 is operable between a jaws-released condition and ajaws-locked condition and adapted so that in the jaws-locked conditionthe clamping mechanisms 95 are able to secure corresponding fixed andsliding butt fusion jaws 41 or 42 on the frame 10 and carriage bearings14 and 24, respectively.

Each of the jaws 41 or 42 is further adapted to permit its rotationabout its center vertical axis in its corresponding bearing 14 and 24 inthe jaws-released condition. Rotation of the jaws 41 or 42 about theirrespective axes is forward and rearward of the vertical reference plane17 centered between the guide rails 11 and 12. The frame 10 and thecarriage 20 each have an identical rotational index 26 and each jaw 41or 42 has an angle registration line 28 at the vertical reference plane17 co-operable with a corresponding index 26 to universally indicate anangular position of the jaw 41 or 42 in relation to its respective frame10 or carriage 20.

In the distal butt fusion configuration, each jaw 41 and 42 is rotateduntil its angle registration line 28 is registered at a desired angleforward of the vertical reference plane 17 between the guide rods 11 and12. The arcuate channel 69 in the bottom surface of the sliding jaw 42straddles the drive screw 112 of the drive mechanism 30 and issufficiently wide to permit the carriage 20 to rotate at least as muchas 22.5° forward and rear of the vertical reference plane 17 between theguide rails 11 and 12. If the angles of both jaws 41 and 42 areforwardly rotated 22.5°, a 45° degree miter results and a 90° turn canbe accomplished with two miter joints. Each jaw 41 or 42 may furtherhave a telescoping pipe support 71 or 79 mounted on and rotatable withthe jaw 41 or 42.

Turning now to FIG. 7B, for butt fusing pipe in a proximal miteredalignment relative to the operator, the pipe fusion machine M is thesame as described in reference to FIG. 7A but each jaw 41 and 42 isrotated until its angle registration line 28 is registered at a desiredangle rearward of the vertical reference plane 17 between the guide rods11 and 12.

Looking at FIG. 8A, for use in socket fusion of polyolefin pipe atmitered angles, the machine M has a frame 10 with a reference end 15 anda drive end 16 supporting spaced apart parallel guide rails 11 and 12therebetween in a horizontal plane. The carriage 20 is mounted to slidelongitudinally on the guide rails 11 and 12. One vertically alignedbearing 14 is centered between the guide rails 11 and 12 on thereference end 15 of the frame 10. Another vertically aligned bearing 24is centered between the guide rails 11 and 12 on the carriage 20. Eachof the vertically aligned bearings 14 and 24 has an identical clampingmechanism 95 thereon. The carriage drive mechanism 30 proximate thedrive end 16 of the frame 10 is configured to reciprocate the carriage20 on the guide rails 11 and 12 in response to directional force appliedto the carriage 20. The socket fusion fixed bracket 83 is adapted formounting on the frame bearing 14. The sliding socket fusion bracket 83is adapted for mounting on the carriage bearing 24. Each of the brackets83 is adapted for engagement with a corresponding clamping mechanism 95of a corresponding bearing 14 and 24. The clamping mechanisms 95 areoperable between a brackets-released condition and a brackets-lockedcondition and are adapted in their bracket-locked condition to securethe socket fusion fixed bracket 83 and the sliding socket fusion bracket83 on the frame and carriage bearings 14 and 24, respectively. The fixedand sliding socket fusion brackets 83 each have a mechanical driveassembly 80 supporting fixed and sliding socket fusion jaws 43 and 44,respectively, for opening and closing front and rear components 87 and88 or 81 and 82 of respective jaws 43 and 44 by sliding reciprocation toand from a center point 89 between the guides 84 of the carriage 20 onrespective axes transverse to the guide rails 11 and 12 of the frame 10.

Each of the brackets 83 is rotatable about its center vertical axisforward of and rearward of the vertical reference plane 17 centeredbetween the guide rails 11 and 12. The frame 10 and the carriage 20 eachhave an identical rotational index 26 and each bracket 83 has an angleregistration line 28 at the vertical reference plane 17 co-operable witha corresponding index 26 to universally indicate an angular position ofthe bracket 83 in relation to a respective frame 10 or carriage 20.

In the distal socket fusion configuration, each bracket 83 is rotateduntil its angle registration line 28 is registered at a desired angleforward of the vertical reference plane 17. The arcuate channel 69 inthe bottom surface of the bracket 83 straddles the drive screw 112 ofthe drive mechanism 30 and is sufficiently wide to permit the carriage20 to rotate at least as much as 5° forward and rear of the verticalreference plane 17. If the angles of both jaws 43 and 44 are forwardlyrotated 5°, a 10° degree miter results.

Turning now to FIG. 8B, for socket fusing pipe in a proximal miteredalignment relative to the operator, the pipe fusion machine M is thesame as described in reference to FIG. 8A but each bracket 83 is rotateduntil its angle registration line 28 is registered at a desired anglerearward of the vertical reference plane 17.

Looking at FIG. 9A, the machine M is seen in the butt fusion miteredjoint configuration of FIG. 7B with pipes P mitered and ready for fusionat a proximal angle from the viewpoint of an operator standing in frontof the machine M. In FIG. 9B, the machine M is seen in the socket fusionmitered joint configuration of FIG. 8A with a socket S and a pipe Pmitered and ready for fusion at a distal angle from the viewpoint of anoperator standing in front of the machine M.

The machine M illustrated in the drawings is capable of use in any orall of the butt and the socket fusion configurations herein discussed.

Thus, it is apparent that there has been provided, in accordance withthe invention, a pipe fusion machine that fully satisfies the objects,aims and advantages set forth above. While the invention has beendescribed in conjunction with a specific embodiment thereof, it isevident that many alternatives, modifications and variations will beapparent to those skilled in the art and in light of the foregoingdescription. Accordingly, it is intended to embrace all suchalternatives, modifications and variations as fall within the spirit ofthe appended claims.

What is claimed is: 1-3. (canceled)
 4. For fusing polyolefin pipe, amachine comprising: a frame having a reference end and a drive endsupporting spaced apart parallel guide rails therebetween in ahorizontal plane; a carriage mounted to slide longitudinally on saidguide rails; one vertically aligned bearing centered between said guiderails on said reference end of said frame; another vertically alignedbearing centered between said guide rails on said carriage; each of saidvertically aligned bearings having an identical clamping mechanismthereon; a carriage drive mechanism proximate said drive end of saidframe and configured to reciprocate said carriage on said guide rails inresponse to directional force applied thereto; a fixed butt fusion jawand a fixed socket fusion jaw, each adapted for mounting on said framebearing; a sliding butt fusion jaw and a sliding socket fusion jaw, eachadapted for mounting on said carriage bearing; each of said jaws beingadapted for engagement with a corresponding said clamping mechanism of acorresponding said bearing; and said clamping mechanisms being operablebetween a jaws released condition and a jaws locked condition andadapted in said jaws locked condition to secure one of: a fixed buttfusion jaw and a sliding butt fusion jaw and a fixed socket fusion jawand a sliding socket fusion jaw on said frame and carriage bearings,respectively.
 5. A machine according to claim 4, each of said jaws beingfurther adapted to permit rotation thereof about a center vertical axisthereof in a corresponding said bearing in said jaws released condition.6. A machine according to claim 5, each of said jaws being rotatableabout said center vertical axis thereof forward of and rearward of avertical plane centered between said guide rails.
 7. A machine accordingto claim 6, said frame and said carriage each having an identicalrotational index and each said jaw having an angle registration linethereon at the vertical plane co-operable with a corresponding saidindex to universally indicate an angular position of said jaw inrelation to a respective said frame and said carriage.
 8. A machineaccording to claim 5, each said jaw further comprising a telescopingpipe support mounted on and rotatable with said jaw.
 9. A machineaccording to claim 4 for use in socket fusion of polyolefin pipe atmitered angles, the machine further comprising: a frame having areference end and a drive end supporting spaced apart parallel guiderails therebetween in a horizontal plane; a carriage mounted to slidelongitudinally on said guide rails; one vertically aligned bearingcentered between said guide rails on said reference end of said frame;another vertically aligned bearing centered between said guide rails onsaid carriage; each of said vertically aligned bearings having anidentical clamping mechanism thereon; a carriage drive mechanismproximate said drive end of said frame and configured to reciprocatesaid carriage on said guide rails in response to directional forceapplied thereto; a fixed socket fusion bracket adapted for mounting onsaid frame bearing; a sliding socket fusion bracket adapted for mountingon said carriage bearing; each of said brackets being adapted forengagement with a corresponding said clamping mechanism of acorresponding said bearing; said clamping mechanisms being operablebetween a brackets released condition and a brackets locked conditionand adapted in said brackets locked condition to secure said fixedsocket fusion bracket and said sliding socket fusion bracket on saidframe and carriage bearings, respectively; and said fixed and slidingsocket fusion brackets each having a mechanical drive assemblysupporting fixed and sliding socket fusion jaws, respectively, foropening and closing respective said jaws by sliding reciprocation to andfrom a center point between said guide rails of said carriage onrespective axes transverse to said guide rails.
 10. A machine accordingto claim 5, each of said brackets being rotatable about said centervertical axis thereof forward of and rearward of a vertical planecentered between said guide rails.
 11. A machine according to claim 6,said frame and said carriage each having an identical rotational indexand each said bracket having an angle registration line thereon at thevertical plane co-operable with a corresponding said index touniversally indicate an angular position of said bracket in relation toa respective said frame and said carriage.